Alaoceras
Encyclopedia
Alaoceras is an ammonoid cephalopod from the upper Paleozoic
included in the goniatitid family Cravenoceratidae
, named by Ruzhentsev & Bogoslovskaya in 1971.
Alaoceras is characterized by its generally subdiscoidal shell with moderatley involute whorls and a wide or moderately wide umbilicus, ornamented with sharply defined lamellae, very weak and sometimes disappearing lirae, and elongated protuberances on the umbilical wall. Normally there are 1 or 2 constrictions per revolution. The suture is goniatitic with a widely diverging bifurcated ventral lobe in which the height of the median saddle is less than half of the whole lobe.
Alaoceras is probably derived from Pachylyroceras
, which it resembles overall.
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
included in the goniatitid family Cravenoceratidae
Cravenoceratidae
The Cravenoceratidae is one of six families included in the ammonoid superfamily Neoglyphiocerataceae, which lived during the latter part of the Paleozoic era....
, named by Ruzhentsev & Bogoslovskaya in 1971.
Alaoceras is characterized by its generally subdiscoidal shell with moderatley involute whorls and a wide or moderately wide umbilicus, ornamented with sharply defined lamellae, very weak and sometimes disappearing lirae, and elongated protuberances on the umbilical wall. Normally there are 1 or 2 constrictions per revolution. The suture is goniatitic with a widely diverging bifurcated ventral lobe in which the height of the median saddle is less than half of the whole lobe.
Alaoceras is probably derived from Pachylyroceras
Pachylyroceras
Pachylyroceras is a large, generally subglobular, Upper Mississippian gonitite and included in the cephalopod subclass Ammonoidea.-Recognition:...
, which it resembles overall.